Foreign ministers from six global powers are gathering in the Swiss Resort of Lausanne as the critical Iranian nuclear talks there near a climax. Amid calls for last minute compromise, French Foreign Minister Laurent Fabius has said a deal's possible, but Tehran must make what he called 'new efforts.'

French foreign minister Fabius Laurent and his German counterpart Frank-Walter Steinmeier join other top US and Iranian diplomats as the major powers bring to bear their combined influence in a final critical weekend of talks.

As the foreign ministers gathered, negotiations appeared to be closing in a two to three page framework agreement that could form the basis of a long-term accord. But important work remained said the French foreign minister.

"What is obviously very important is the content itself of the commitments that must be taken, but also I want to insist on the transparency of the mechanism and the control, so that we are sure the commitments taken are respected," said Laurent Fabius, French FM.

Significantly, Fabius said Tuesday's deadline for the tortuous negotiations was not final. If Iran and the six powers represented around the table could reach agreement it would be historic, ending a decade-long standoff over Iran's nuclear programme. It would 'lay to rest' international fears the country has been developing nuclear weapons. Iran always insisting its nuclear research was for strictly peaceful purposes.

Iran's foreign minister Javad Zarif said his government was politically committed to engagement.

"We are prepared to work diligently in order to move forward and I think there is every indication we can in fact move forward. As I've said all along, Iran has made a decision, a political decision to go for engagement with dignity. I believe our negotiating partners also need to make this decision," he said.

Evidently, the talks are close but roadblocks still stand in the path of final agreement. If negotiators can find a way round it'll be a diplomatic triumph, but they're not there quite yet and the tone appears to be shifting.